all: finish scripts, imp names

docker/dns-bind.awk

@@ -0,0 +1,12 @@
+BEGIN { num = 0; prev_line = 0; }
+/^[^[:space:]]/ { is_dns = /^dns:/; }
+/^[[:space:]]+bind_hosts:/ { is_dns_bh = 1; if (is_dns_bh && is_dns) prev_line = FNR; }
+/^[[:space:]]+- .+/ {
+    if ((FNR - prev_line) == 1 && is_dns_bh) { addrs[num++] = $2; prev_line = FNR; }
+}
+/^[[:space:]]+port:/ { if (is_dns) port = $2; }
+END {
+    for (i = 0; i < num; i++) {
+        if (match(addrs[i], ":")) print "[" addrs[i] "]:" port; else print addrs[i] ":" port;
+    }
+}

docker/healthcheck.sh

@@ -0,0 +1,70 @@
+#!/bin/sh
+
+# AdGuard Home Docker healthcheck script
+
+# Exit the script if a pipeline fails (-e), prevent accidental filename
+# expansion (-f), and consider undefined variables as errors (-u).
+set -e -f -u
+
+# Function log is an echo wrapper that writes to stderr if the caller requested
+# verbosity level greater than 0.  Otherwise, it does nothing.
+log() {
+	# if [ "$VERBOSE" -gt '0' ]
+	# then
+		echo "$1" 1>&2
+	# fi
+}
+
+home_dir="/opt/adguardhome"
+readonly home_dir
+
+filename="${home_dir}/conf/AdGuardHome.yaml"
+readonly filename
+
+if ! [ -f "$filename" ]
+then
+    wget "http://127.0.0.1:3000" -O /dev/null || exit 1
+
+    exit 0
+fi
+
+# Parse.
+
+help_dir="${home_dir}/scripts"
+readonly help_dir
+
+web_host=$(awk -f "${help_dir}/web-bind.awk" "$filename")
+readonly web_host
+
+dns_hosts=$(awk -f "${help_dir}/dns-bind.awk" "$filename")
+readonly dns_hosts
+
+if [ "$dns_hosts" == '' ]
+then
+    log "No DNS bindings could be retrieved from $filename"
+
+    exit 1
+fi
+
+# TODO(e.burkov):  Deal with 0 port.
+first=$(echo $dns_hosts | head -n 1)
+case $first
+in
+(*":0")
+    log "0 port is not supported"
+
+    exit 1
+    ;;
+(*)
+    # Go on.
+    ;;
+esac
+
+# Check
+
+wget "http://${web_host}" -O /dev/null || exit 1
+
+echo "$dns_hosts" | while read -r host
+do
+    nslookup -type=a localhost $host || exit 1
+done

docker/web-bind.awk

@@ -0,0 +1,3 @@
+/^bind_host:/ { host = $2 }
+/^bind_port:/ { port = $2 }
+END { if (match(host, ":")) print "[" host "]:" port; else print host ":" port; }

internal/dnsforward/dns64.go

@@ -36,8 +36,6 @@ func (s *Server) setupDNS64() {
 // valid IPv4.  It panics, if there are no configured DNS64 prefixes, because
 // synthesis should not be performed unless DNS64 function enabled.
 func (s *Server) mapDNS64(ip netip.Addr) (mapped net.IP) {
-	// Don't mask the address here since it should have already been masked on
-	// initialization stage.
 	pref := s.dns64Pref.Masked().Addr().As16()
 	ipData := ip.As4()
 

scripts/make/Dockerfile

@@ -57,8 +57,15 @@ EXPOSE 53/tcp 53/udp 67/udp 68/udp 80/tcp 443/tcp 443/udp 784/udp\
 
 WORKDIR /opt/adguardhome/work
 
+# Install helpers for healthcheck.
+COPY --chown=nobody:nogroup\
+	./${DIST_DIR}/docker/scripts\
+	/opt/adguardhome/scripts
+
 ENTRYPOINT ["/opt/adguardhome/AdGuardHome"]
 
+HEALTHCHECK --interval=30s --timeout=10s --retries=3 CMD [ "/opt/adguardhome/scripts/healthcheck.sh" ]
+
 CMD [ \
 	"--no-check-update", \
 	"-c", "/opt/adguardhome/conf/AdGuardHome.yaml", \

scripts/make/build-docker.sh

@@ -105,6 +105,10 @@ cp "${dist_dir}/AdGuardHome_linux_arm_7/AdGuardHome/AdGuardHome"\
 cp "${dist_dir}/AdGuardHome_linux_ppc64le/AdGuardHome/AdGuardHome"\
 	"${dist_docker}/AdGuardHome_linux_ppc64le_"
 
+# TODO(e.burkov):  !! do better
+cp -R "./docker"\
+	"${dist_docker}/scripts"
+
 # Don't use quotes with $docker_tags and $debug_flags because we want word
 # splitting and or an empty space if tags are empty.
 $sudo_cmd docker\